////////////////////////////////////////////////////////////////////////////////
// Copyright (c) 2009 Daniel F. Hanson
// 
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to
// deal in the Software without restriction, including without limitation the
// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
// sell copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
// 
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.
////////////////////////////////////////////////////////////////////////////////

using System.Collections.Generic;

namespace SilverLua.Compiler
{
   internal class FunctionCallNode : PrefixExpressionNode
   {
      internal PrefixExpressionNode Function { get; private set; }
      internal string Method { get; private set; }
      internal ExpressionNode[] Args { get; private set; }

      internal FunctionCallNode(PrefixExpressionNode func, ExpressionNode[] args)
      {
         Function = func;
         Method = null;
         Args = args;
      }

      internal FunctionCallNode(PrefixExpressionNode func, string method, ExpressionNode[] args)
      {
         Function = func;
         Method = method;
         Args = args;
      }

      internal override void EvaluateTo(int register, Parser parser, int currentChunk)
      {
         EvaluateNode function = Function.Evaluate(parser, currentChunk);
         int argBegin = 0;
         int argCount = 0;
         
         if (Method != null)
         {
            argCount = Args.Length + 1;
            argBegin = parser.ChunkList[currentChunk].AllocateTempRegisters(argCount);
            
            parser.ChunkList[currentChunk].Add(new Instruction(Opcode.Move,
                                                               new[] { OperandType.Value,
                                                                       OperandType.StringLiteral },
                                                               new[] { argBegin,
                                                                       parser.ChunkList[currentChunk].ResolveString(Method) }));
            
            for (int i = 0; i < Args.Length; ++i)
            {
               Args[i].EvaluateTo(argBegin + i + 1, parser, currentChunk);
            }
         }
         else
         {
            argCount = Args.Length;
            argBegin = parser.ChunkList[currentChunk].AllocateTempRegisters(argCount);

            for (int i = 0; i < Args.Length; ++i)
            {
               Args[i].EvaluateTo(argBegin + i, parser, currentChunk);
            }
         }
         
         parser.ChunkList[currentChunk].Add(new Instruction(Opcode.Call,
                                                            new[] { function.OperandType,
                                                                    OperandType.IntegerLiteral,
                                                                    OperandType.IntegerLiteral },
                                                            new[] { function.OperandValue,
                                                                    argBegin,
                                                                    argCount }));
         parser.ChunkList[currentChunk].Add(new Instruction(Opcode.Move,
                                                            new[] { OperandType.Value,
                                                                    OperandType.Return },
                                                            new[] { register,
                                                                    0 }));
      }
   }
}
